Methods of smooth-rolling and deep-rolling the bearing pins of multi-crank or multi-stroke crankshafts are generally known. In this context the deep-rolling operation is frequently limited to the area of the transition radius or gusset between the bearing pin and the crank web or cheek. It is a predominant goal in this field to simultaneously roll all of the bearing pins, including the main bearing pins and all of the connecting rod crank pins. Such a method is most economical as long as large numbers of the same type of crankshafts are being manufactured. The economy is achieved because the crankshaft is completely machined in a single work operation. The original machines built to achieve this goal were specific application machines built for a single exactly defined crankshaft type having one specified set of dimensions. Unfortunately, such machines and the methods they employed were quite uneconomical when various different crankshaft types, namely crankshafts having different dimensions, were to be produced and rolled in low number production runs. In those cases it would be necessary to build a separate rolling machine for each different crankshaft type. European Patent Publication No. 0,167,659 discloses adjustable crankshaft rolling machines which overcome the above described problem, but which are not able to simultaneously roll all of the bearing pins. However, these machines could easily be adjusted to various crankshaft dimensions and would then be used to successively roll the various bearing pins of each crankshaft. U.S. Pat. No. 4,290,238 discloses a similar apparatus. However, these two machines are very slow and thus uneconomical in machining the crankshafts.
In all of the above described prior art machines the bearing pin rolling devices are arranged respectively next to each other in such a manner that two directly neighboring bearing pins may be rolled simultaneously in one rolling operation. However, this method and arrangement of the rolling tools of the rolling devices is not possible for crankshafts with extremely closely spaced connecting rod crank pins because there is not sufficient space for arranging the rolling devices directly next to each other. In such cases it is only possible to use a single rolling device to individually roll each connecting rod crank pin respectively in succession. The rolling process thereby becomes slow and uneconomical even for a series production of a relatively small number production run.